Scum or floating oil or floating oil separation device has been widely used in liquid separation industry, such as grease trap, oil water separator, etc. The scum or floating oil or floating oil separated by these devices will be discharged through a skimming pipe or by a scum or floating oil scraper. However, a large amount of raw liquid constituents are contained in the scum or floating oil or floating oil discharged from these scum or floating oil or floating oil separation devices in current application. A relatively high percentage of raw liquid content is contained in the scum or floating oil or floating oil, which cannot return to original system for recycling, hence causing a significant waste of raw liquid. Furthermore, the scum or floating oil containing a large amount of raw liquid increases the workload of the next step. Besides, the scum or floating oil is easily deteriorated during the process of being gathered and concentrated on the surface of these separation devices, giving out an odor to the surrounding environment, causing pollution. Moreover, it is very difficult for the existing scum or floating oil separation devices to effectively and promptly remove high-viscosity and high-concentration scum or floating oil to the outside of the separation devices. The main causes for above defects include: 1) unreasonable design of concentration device; scum or floating oil cannot be concentrated for a long period of time in the device, so as to reduce the liquid content of the scum or floating oil; 2) during the scum or floating oil collection process, a conventional skimming pipe or scum or floating oil scraper relies on scum or floating oil gravity or the scum or floating oil scraper pushes the scum or floating oil to the scum or floating oil receiving mouth; the process when the scum or floating oil moves laterally on the liquid surface interferes with the normal separation, and scum or floating oil movement will cause loss of buoyancy by a part of scum or floating oil, allowing it to fall into the raw liquid, thus negatively affecting the separation. In order to solve this difficult problem, there is a scum or floating oil collection method in prior art in which the scum or floating oil is scooped out of the liquid surface by a spoon. This scum or floating oil-collecting process avoids the lateral movement of the scum or floating oil, having less interference to the separation, but the scum or floating oil scooped into the scum or floating oil conveying pipe still need to be discharged on gravity. Thus, the device requires scum or floating oil to have a certain degree of liquidity; for scum or floating oil having a low liquid content, high viscosity and low fluidity, the device will fails to discharge it. In addition, it is difficult for the device to obtain scum or floating oil with low raw liquid content and high concentration.